//
//  TJAuthCode.m
//  Unionpay
//
//  Created by admin on 2021/11/1.
//  Copyright © 2021 YAZX. All rights reserved.
//

#import "TJAuthCode.h"

// 背景随机颜色
# define kRandomColorAL [UIColor colorWithRed:arc4random() % 256 / 256.0 green:arc4random() % 256 / 256.0 blue:arc4random() % 256 / 256.0 alpha:0.5]
// 干扰线随机颜色
# define kRandomColor [UIColor colorWithRed:arc4random() % 256 / 256.0 green:arc4random() % 256 / 256.0 blue:arc4random() % 256 / 256.0 alpha:1.0]
// 干扰线数量
# define kLineCount 4
// 干扰线宽度
# define KlineWidth 1.f
// 验证码数量
# define kCharCount 4
// 验证码大小
# define kFontSize (arc4random() % 15 + 20)

@implementation TJAuthCode

- (instancetype)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        self.layer.cornerRadius = 5.f;
        self.layer.masksToBounds = YES;
        self.backgroundColor = [UIColor whiteColor];
        
        [self getAuthcode];
    }
    return self;
}

# pragma mark 获取随机验证码
- (void)getAuthcode
{
    // 字符样本
    NSArray *numArr = @[@"0", @"1", @"2", @"3", @"4", @"5", @"6", @"7", @"8", @"9"];
    NSArray *letterArr = @[@"A",@"B",@"C",@"D",@"E",@"F",@"G",@"H",@"I",@"J",@"K",@"L",@"M",@"N",@"O",@"P",@"Q",@"R",@"S",@"T",@"U",@"V",@"W",@"X",@"Y",@"Z",@"a",@"b",@"c",@"d",@"e",@"f",@"g",@"h",@"i",@"j",@"k",@"l",@"m",@"n",@"o",@"p",@"q",@"r",@"s",@"t",@"u",@"v",@"w",@"x",@"y",@"z"];
    NSMutableArray *_dataArray = [NSMutableArray array];
    [_dataArray addObjectsFromArray:numArr];
    [_dataArray addObjectsFromArray:letterArr];
    
    _authCodeStr = [[NSMutableString alloc] initWithCapacity:kCharCount];
    // 随机字符拼接验证码
    for (int i = 0; i < kCharCount; i++) {
        NSInteger index = arc4random() % (_dataArray.count - 1);
        NSString *tempStr = [_dataArray objectAtIndex:index];
        _authCodeStr = (NSMutableString *)[_authCodeStr stringByAppendingString:tempStr];
    }
}

# pragma mark 点击界面切换验证码
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
    [self getAuthcode];
    
    // setNeedsDisplay 调用 drawRect 方法来实现 view 的绘制
    [self setNeedsDisplay];
}

# pragma mark 绘制

- (void)drawRect:(CGRect)rect
{
    [super drawRect:rect];
    
    // 设置随机背景色
//    self.backgroundColor = kRandomColorAL;
    
    // 根据要显示的验证码字符串，根据长度，计算每个字符串显示的位置
    NSString *text = [NSString stringWithFormat:@"%@", _authCodeStr];
    
    CGSize cSize = [@"A" sizeWithAttributes:@{NSFontAttributeName: [UIFont systemFontOfSize:20.f]}];
    
    int width = rect.size.width / text.length - cSize.width;
    int height = rect.size.height - cSize.height;
    
    CGPoint point;
    
    // 依次绘制每一个字符，设置大小、颜色、样式
    float pX, pY;
    for (int i = 0; i < text.length; i++)
    {
        pX = arc4random() % width + rect.size.width / text.length * i;
        pY = arc4random() % height;
        point = CGPointMake(pX, pY);
        
        unichar c = [text characterAtIndex:i];
        NSString *textC = [NSString stringWithFormat:@"%C", c];
        UIFontDescriptor *attributeFontDescriptor = [UIFontDescriptor fontDescriptorWithFontAttributes:@{UIFontDescriptorFamilyAttribute: @"Marion", UIFontDescriptorNameAttribute: @"HanziPenSC-W3", UIFontDescriptorSizeAttribute: @40.0, UIFontDescriptorMatrixAttribute: [NSValue valueWithCGAffineTransform:CGAffineTransformMakeRotation(M_1_PI * (arc4random() % 2))]}];
        
        UIFont *font = [UIFont fontWithDescriptor:attributeFontDescriptor size:kFontSize];
        UIColor *color = kRandomColor;
        [textC drawAtPoint:point withAttributes:@{NSFontAttributeName: font, NSForegroundColorAttributeName: color}];
    }
    
    // 调用drawRect：之前，系统会向栈中压入一个CGContextRef，调用UIGraphicsGetCurrentContext()会取栈顶的CGContextRef
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextSetLineWidth(context, KlineWidth);
    
    // 绘制干扰线
    for (int i = 0; i < kLineCount; i++) {
        UIColor *color = kRandomColor;
        CGContextSetStrokeColorWithColor(context, color.CGColor);  // 设置线条填充色
        
        // 设置线的起点
        pX = arc4random() % (int)rect.size.width;
        pY = arc4random() % (int)rect.size.height;
        CGContextMoveToPoint(context, pX, pY);
        // 设置线的终点
        pX = arc4random() % (int)rect.size.width;
        pY = arc4random() % (int)rect.size.height;
        CGContextAddLineToPoint(context, pX, pY);
        // 画线
        CGContextStrokePath(context);
    }
}

@end
